Gas pump



Apg. 6, 1946. P. J. VOEAUX GAS PUMP Filed July 17, 1945 2 Sheets-Sheet 1 Aug.6,1946.A i J, VOREAUX y 2,405,475

GASPUMP l FledJuly 17,. 1945 l 2 Sheets-Sheet 2 Patented Aug. 6, 1946 GAS PUMP Paul Jean Voreaux, Saint-Cloud, France, assigner to Raymond Gentil, Neuilly-sur-Sene, France Application July 17, 1945, Serial No. 605,484 In France May 30, 1942 s 5 Claims.

My invention relates t gas pumps of the type comprising a piston reciprocated in a cylinder, and it is a primary object to simplify their construction while improving their operation.

According to this invention, the piston pin is used as a swinging valve and for this purpose, is made as a tube or hollow body through the inner space of which gas to be compressed or forced out is allowed to pass.

Suitable opening or ports are provided through the wall of the tube or hollow body and the piston end. wall in order that gas may flow through said piston end wall at proper time; thus either intake valves or intake and outlet valves are dispensed with, while no supplemental members are added.

In the case of a pump with discharge valves, the gas intake duct communicating with the tube or hollow body, used as a piston pin, is uncovered by the upper face of the piston at the end of the stroke.

The intake duct may be a single bore in the cylinder or cylinders, parallel with the distributing piston pin or pins and feeding all cylinders through said piston pins.

In the case of a pump designed to have no valves, the tube or hollow body used as a piston pin is formed with two recesses, provided for instance by an intermediate partition. One of the recesses is in communication with intake, the other one with discharge, and they are successively brought in communication with the cylinder as the piston pin swings.

My invention also comprises a combination of the aforesaid arrangements to obtain a multistage operation.

The following description with reference to the appended drawings given solely by way of example, will show how my invention may be carried out.

Fig. 1 is a longitudinal section of a gas pump with a cylinder having a discharge valve, the section being taken along line I-I on Fig. 2.

Fig. la shows the piston separately in elevation view.

Fig. 2 is a transverse section taken along line II-II on Fig. 1.

Fig. 2a is a detail view corresponding to Fig. 2, the piston being shown alone.

Fig. 3 is a partial section taken along lines III- III on Figs. 1 and 4.

. Fig. 4 is a plan view corresponding to Fig. 3.

Figs. 5 and 6 show modications of Fig. 4.

Fig. 7 shows a modification of Fig. 1 in the case of a two-cylinder pump.

Fig. 8 shows a further modicaticn of Fig. 1, in the case of a one-cylinder pump without any intake and discharge valves.

Figs. 9 and 10 are diagrammatic sections taken along lines X-X and Y-Y on Fig. 8.

Fig. 11 shows a modication of Fig. 8 in the case of a pump with two compression stages.

The gas pump shown on Figs. 1 and 2 comprises a cylinder l, a piston 2, a connecting rod 3, a crankshaft 4 revolving for instance in the direction of arrow F (Fig. 2), a head 5 closing cylinder I and in which an outlet valve is mounted. The hollow pistonpin 'l which has a diameter larger than usual, is secured to an end connecting rod 3 by a transixing pin 8 or any other suitable means. Pin 1 is provided with `ports 9 adapted to register with ports l0 in the end wall of piston 2. Bored in cylinder l in parallel relationship with the piston pin 'l is a hole ll operating as an inlet duct and permanently communicating with the hollow portion of pin 'l through a large opening 2 in the piston skirt (Figs. la and 2.a).

The operation is as follows: as suction stroke f is beginning (upper dead centre of piston 2),

ports 9 and l0 are positioned as shown on Fig. 3 and do not register. While piston 2 moves down, pin 1' swings in the direction of arrow f (Fig. 3) and ports 9 come into register with ports I9, so that gas sucked through duct Il into hollow piston pin 'l is allowed to pass through ports 9 and l0 into the upper cylinder portion; at the bottom end of down stroke (Fig. 1), duct ll may advantageously be uncovered by the upper face of piston 2 and thus in direct communication with the cylinder, to complete intake; a port or recess lla may also be provided opposite duct Il to place the hollow portion of pin 'I in oommunication withthe cylinder, in this dead centre position, so as to complete filling of the cylinder upper chamber. In said bottom dead centre p0- sition, ports 9 have resumed their former position shown on Fig. 3, and as piston pin 1 is about to swing in anticlockwise direction when piston 2 moves up to resume said position of Fig. 3 at the end of upwards stroke, it. will be realized that throughout the discharge stroke, communication is broken between ports 9 and I0; any gas conned between piston 2 and cylinder head 5 is then forced past outlet valve 8.

Hollow piston pin 'I and the end wall of piston 2 may have two rows of ports, and in each row, there may be two ports (Fig. 4) or more than two (Fig. 5); instead of cylindrical ports, I may also provide parallel slots as illustrated at Illa on Fig. 6. as shown on Fig. 7; the inlet duct then passes through both cylinders as seen at II, IIb and I Ia; suction of gas into the second cylinder takes place through opening IIb and the hollow pin of the first cylinder, the double cylinder pump operating just asthe one cylinder pump above referred to. v

I may also construct a pump according to this invention without any inlet and outlet valves as.

The pump may have two cylinders shown on Fig. 8, suction and discharge being controlled by the piston hollow pin. For this purpose, said pin is divided by a partition I2 into 2. The combination of claim l, the side recesses in the piston forming one bore therethrough, and

the ducts in the cylinder being bored in diamettwo recesses or compartments I3 and I4;v recess I3 communicates with intake'bo're or duct II in cylinder I while recess I4 communicates with a bore or duct I5 in the opposite wall of said cylinder. Moreover, bores sa, Ia and 9b, Ib are provided in the wall of the piston pin and the'pisto'n end wall respectively; bores Iia may be arranged like bores lllb but bores Sa are shifted to the left (Fig. 9) assuming that the crankshaft revolves in the direction of arrow Fo, while bores 9b are shifted to the right (Fig. l0).

The pump operates as follows:

As the piston moves down, bores 9a in the piston pin register with bores Illa and consequently the upper cylinder chamber is placedin communication with recess I 3 and inlet duct II.V While the piston moves up, bores I 0a are closed, and bores 10b are placed in communication with recess Id and discharge. duct I5 through bores 9b.

The foregoing arrangement more particularly applicable to vacuum pumps, will advantageously be employed in the first stage of a two-stage pump.

Fig. 11 shows a valveless two-stage pump. Gas is sucked in the iirst stage cylinder through duct I I as above described, forced from the rst stage cylinder and sucked into the second stage cylinder througha duct I6 providing a communication between said cylinders, then nally discharged from the second stage cylinder through duct lia.

Ducts II, I6 and I5a are obtained from one bore through both cylinders.

For constructinga two-stage vacuum pump, it is preferable to use in the rst stage an intake and discharge device controlled by piston pin as shown on Fig. 8, and in the second stage a device with intake control by pin and discharge control by automatic valve as shown on Figs. 1 and 2.

What I claim is:

1. A valveless pump which comprises a cylinder having two spaced apart side ducts through its wall; a. piston reciprocably movable inthe cyll;

inder, having a side bored recess for communication with one of the ducts in the cylinder, and a second side recess for communication with the vrically opposite positions, the recesses in the pin vbeing bored in opposite ends thereof to leave an l .intermediate partition.

. 3. In a pump of the type described, the combilso other duct in the cylinder; a coupling pin borne y in the iirst named recess for swinging Vmotion through its wall; a piston reciprocably movable in said cylinder, having a bored side recess so located as to be in open communication with said duct as the piston is reciprocated in said cylinder and to provide between said recess and the upper face of said piston, a piston solid portion of less thickness than the diameter of said duct, whereby said duct communicates both with said cylinder above said piston and with said recess when the piston reaches its lowermost position; a coupling pin having a recess in open communication with the recess in the piston, borne in said bored recess of the piston for swinging motion therein; and a connecting rod fast with said pin, adapted in operation to impart a swinging motion thereto; the piston and the pin having each a port therethrough, said ports being so drected and located as to register .for a predetermined position of the piston with respect to the cylinder for placing' the inner space of said cylinde'r in communication with the pin recess.

4. In a pump according to claim 3, characterized in that the cylinder has a recess in its Wall, lying opposite, and of the same diameter as the side intake duct.

5. In a pump of the type described, the combination ci a cylinder having a side intake duct through its wall; a piston reciprocably movable in'said cylinder, having one cross bore therethrough and at least one port extending from the working face of said piston to said bore; an open-ended tubular wrist pin borne in said piston bore for swinging motion therein, said pin having a port through its wall adapted and arranged to register with the port in said piston for a predetermined position of the piston with respect to said cylinder so as to place the inner space of said cylinder in communication with the inside of said wrist pin; a connecting rod fast with said wrist pin; a crank-shaft coupled with said rod; and means fast with said cylinder for revolubly supporting said crank-shaft in such a position that the piston bore is in open communication through an end thereof with said side intake duct.

PAUL JEAN VORE'AUX. 

